Yesterday saw the publication of the final report of the EPPSE project. This was a large, longitudinal study which began in 1997, describing itself as "the first major study in the UK to focus on the effectiveness of early years education." Since the beginning the project has produced a range of detailed research reports on many aspects of early years provision and education. Very useful if you're studying this area!
The final report from EPPSE is available here, and has made headlines for its claim that children who benefit from pre-school education get higher GCSEs. The project website is well worth a visit as you can access everything else that's been published in recent years - here's the link.